/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicMeshOverlay.h
Copy the Copy overlay to a compact rep, also updating parent references based on the CompactMaps
void CompactCopy ( const [FCompactMaps](API\Runtime\GeometryCore\Util\FCompactMaps) & CompactMaps, const [TDynamicMeshOverlay](API\Runtime\GeometryCore\DynamicMesh\TDynamicMeshOverlay)< RealType, ElementSize > & Copy )